Beard. — Canning of Sardines. 123 



A first view of the sardine industry shows that a variety 

 of packs are produced and by methods apparently quite 

 diverse. Even the same method is seldom alike in any two 

 canneries. Closer study reveals, however, that the produc- 

 tion of all canned sardines is dependent upon a few well 

 defined factors, which are:(l) the fish themselves, including 

 their condition, handling and cleaning; (2) the preparation 

 of the fish for canning; (3) the materials placed in the can 

 with the fish; (4) the canning procedure itself; and, (5) the 

 chemical and physical changes which take place within the 

 can during processing and later storage. Much is known 

 about some of these factors and less about others. In any 

 case, however, good methods of bringing about desired re- 

 sults and of obtaining excellent final products are known and 

 practiced, yet it is reasonable to assume that a better under- 

 standing of underlying principles and of more economical 

 methods of accomplishing the ends sought will be of assis- 

 tance, perhaps to a very material degree. This is especially 

 true concerning factor (2), the preparation of the fish for 

 canning ; and it is for this reason that the investigation has 

 so far been directed into this field. 



The first problem taken up was a study of the changes 

 which take place in oil used for frying sardines. This, 

 because of the rapid deterioration of the oil used, presents a 

 problem of importance, especially in California where pre- 

 cooking in oil is the usual procedure. Under operating 

 conditions, starting with a bath of fresh cottonseed, or other 

 oil, the oil in the fry-bath rapidly darkens in color, becomes 

 viscous and acquires a characteristic paint-like taste and 

 odor. Part of this oil, although perfectly sanitary, finds its 

 way into the canned product with results which are dis- 

 pleasing to some. The expense of frequent renewal of the 

 oil is so large that it is impracticable. Attempts to diminish 

 these effects and to recover the used oil by mechanical or 

 chemical treatment have met with little success. In studying 

 this problem experiments were conducted which show the 

 nature of the changes taking place and indicate the direction 

 in which improvement should be made. 



The results of the investigation may be summarized as 

 follows : Fish oil is present to a greater or less extent in oil 

 used for frying sardines. When the fish are placed in the 

 fry-bath, oil is rendered from them and mixes with the oil 

 already present. Upon removal the cooked fish mechani- 

 cally carry away some of the resulting mixed oils but leave 

 some of their oil, thus increasing the percentage of fish oil 

 in the fry-bath. When fat fish are fried this increase is 

 so rapid that it is only a short time before the fish are being 



